Poor service from MTN

MTN has pathetic service and do not treat their customers fairly. I have been a customer for 30 years and was ******* by a ******* into giving my OTP, I believe they worked for mtn as they had all my details. MTN promised to write of the debt, however 1 and a half years later, this has still not been done despite various assurances from their staff that it will be done. I am very disappointed at their service.